Plane-grate furnace



Feb. 18, 1930. H. SEROG 1,747,738

PLANE GRATE FURNACE Filed Jan. 26, 1929 2 Sheets-Sheet 1 Fig. i

lnveniov:

H o Serog,

Feb. 18, 1930. H. SEROG- 1,747,738

PLANE GRATE FURNACE Filed Jan. 26, 1929 2 Sheets-Sheet 2 Fig 3 f 11 o if/rag,

3) M y z I flit 19s Patented Feb;- 18, 1930 V UNITED STATE 1,74 i,73tl

PATENT: OFFICE nueo snnoe, or VIENNA, AUSTRIA f iPLANE-GBATE summon Application filed January .36, 1929, SerialNo. 335,304, and in Austria February 24, 1928.

Furnaces in which a steam body substantially pyramidal in shape is maintained above the grate surface are known. In case of long plane grates thedifficulty may arise 5 that the steam jets of the steam pyramid which form the top steam layer and extend nearer to the fire bridge are atomized in their lastpart and are no more efficientenough for preventing the hot gases/rising from the grate in the proximity of the fire bridge from directly escaping over thefire bridge. In case of long grates. this results in that the hot gases Lmay partly escape through the v weakened layer of steam in the proximity of the fire bridge and cannot be mixed with the cooler gases rising from the front part ofthe grate; also part of the cooler gases drawn forward by the steam jets may escape near the fire bridge through the thin steam layer. By these facts the desired smokelessness is interfered with and the heating effect to be secured by the steam pyramid is considerably reduced since'the mixture of the take place to the desired extent.

With a view of'o-vercoming these difilcultiesthe present invention consists in providing a set of steam nozzles for forming a substantially pyramid shaped steam body above the grate having its apex in the proximity of the fire door and above the plane ofthe grate, such, pyramid shaped steam body having sides diverging from the said apex towards the grate and the fire bridge in combination with' means for producing a steam layer located above the top side of the said pyramidal steam body by steam jets issuing from nozzles located in the proximityof the fire bridge and above the plane of the grate such steam ets converging to a point in the proximity of the fire door and above the plane of the grate. I r

The annexed-drawings illustrate by way of ;example two constructional forms of theinvention;

Fig. 1 is a longitudinalsection of a furnace according to the invention in a fire, tube boiler. Fig. 2 is a part of a plane view of Fig. 1. Fig. 3 is a longitudinal section of a modified constructional form of a furnace for a water hot gases with the cooler front gases cannot.

tube boiler and Fig. at is a plan view of Fig. 3. In the furnace chamber 10, Figs. 1 and 2 of a plane grate boiler furnace the plane grate 8 is supported at one end at the fire door Wall 11 and at the other end at the fire bridge 9. Above the the door a nozzle set D having a plurality of nozzle holes is provided, such nozzle holes having diverging axes coinciding with the axes of the steam jets and inthat the steam layer produced by the steam jetsl, 2 and 8 issuing from the fire bridge is spread as a protective shield over the hot gases rising fromthe rear part ofthe grate and is at this part, of such a strength,

that the hot gases cannot penetrate any more through thisdense layer and escape directly above the fire bridge, but are deflected to wards thefront where they can mix with the smoke gases supplied from the bottom part of'the steam pyramid. The fact, that the jets 1, 2 and Sort this new steam pyramid are oppositely directed to the steam jets a, 5 and 6 and therebyproduce a draught opposite to that produced by the steam jets 4, 5 and 6, is not objectionable since the jets 1, 2 and 8 mm not exert an intense draught action, at the point where they come near the jets l, 5 and 6 because they are atomized in their last part owing to the length of the grate and cannot at this part overcome the intense draught due to the jets 4, 5 and 6.

In view of the above the draught condi-- tions arethe following: j

The steam jets 1, 2 and 3 lead the hot gases to the cooler burning gases carried by thejets 4, 5 and 6. Besides for securely guiding the hot gases a steam jet 7 is so provided below the steam jets 1, 2 and 3 that it extends centrally below thesteam layer formed by the steam jets 1, 2 and 3. The intensity of the' The hot gases carried by the jets 1, 2, 8 and attainedby an arrangement in which the steam ets coming from the fire bridge are .jets. entering above the fire door.

7 are reversed by being mixed with the cooler smoke gases carried by the jets l, .5 and ,0 owing to the. intense draught action of the jets 4 5 and 6 at the point where they meet, and thus are brought into the centre of the pyramid, where an intimate mixture may take place. Owing to this intimate mixture the combustion is a much more complete one than was possible below the ordinary steam pyramid because the mixing is accompanied by eddies in the gases caused by the opposite draught actions and this method of mixing the gases takes place in a much more efficient niannerbelow the steam pyramid.

In this furnace the steam jets nearer to the fire bridge are blown in directions converging towards the starting point of the steam I This is suitable more particularly for fiue boilers on account of the low height of the furnace, but shows some drawback in furnaces of a greater height such asfor instance in water tube boiler furnaces.

In water tube boilers, having naturally greater grate surfaces on which much greater quantities of fuel are consumed per'unit of time, the short way of the gases resulting from the steam pyramid is not sufficient to bring about intimate mixture of gases with the top air and consequently a reduction ofthe development of smoke is secured, but not the complete consumption of the smoke. It is an object of the present invention to secure this and this object is not directed towards the starting point of the steam jets coming from the fire door wall, but form a converging steam layer being directed towards the fire door wall above 1 the pyramid shaped steam body maintained over the grate surface.

. At the points 70, 80, 90,100 nozzlesD are provided. From these nozzles steam jets are blown which are located above the steam body formed by the steam jets 1 'to 6, and converge towards the fire door wall. The hot gases rising from points near ,to the .fire bridge below the jets l, 2 and 3 which have already lost a considerable part of their strength, are caught by the steam jets 70, 80, 90, 100-having the greatest strength near the fire bridge and are carried towards the fire door and as they are so carried they are intimately mixed with the cooler gases and the top air between the steam jets 1 to 3 and 70, 80, 90, 100 flowing in opposite directions. The gases thus completely burnt then again meet above the steam layer and flow in a vertical direction towards the Water tubesheatingthe-latter. Thereby an undue heating of the brick Walls and vaults is avoided and the heat losses due to radiation are reduced.

What I claim is:

1. Iii-a plane grate furnace comprising a plane grate, a fire door atone end of the grate and a fire bridge at theopposite end of the grate a set of steam nozzles in the proximity of the fire door and above the plane of the grate adapted to produce steam jets forming a steam body substantially in the shape of a pyramid having its apex in the said set of steam nozzles the said steam j'ets'diverging towards the fire bridge and theplane of the fire grate in combination with a'p'lurality of steam nozzles located in the proximity of the fire bridge and above the plane of the fire grate and adapted to projectsteam jets converging towards a point in the proximity of the fire door and above the plane of the grate and located in a plane above the top surface of the said steam body substantially pyramidal in shape.

2.'In a plane grate furnace comprising a planegrate, a fire door at one end of the grate and a fire bridge at the opposite end of the grate a set of steam nozzles in the proximity of the *fire door and above the plane of the grate adapted to produce steam jets forming a steam body substantially in the shape of a pyramid having its apex in the said set of steam nozzles the said steam jets divergingtowards the fire bridge and the-plane ofthe fire grate in combination with a plurality of steam nozzles locatedin the proximity of the fire bridge and above the plane of the fire grate and adapted to project steam jets converging towardsthe apex of the said pyramid and located in a plane above the top surface of the said steam body substantially pyramidal in shape.

3. In a plane grate furnace comprising a plane grate, a fire door at one end of the grate and a fire bridge at the opposite end of the grate aset of steam -nozzles in the proximity of thefire door and above the plane of the grate, adapted to produce steam jets forming a steam body substantially in the shape of a pyramid having its. apex in the said set of steam nozzles the said steam jets diverging towards the fire bridge and the plane of the fire grate in combination with a plurality of steam nozzles located in the proximity of the'fire bridge and above the plane of the grate and adapted to'project steam jets converging towards the apex of the said pyramid and located in a plane above the top surface of the said steam body substantially pyramidal in shape and with an additional nozzle located in line with the said plurality of steam nozzles located in the proximity of the fire bridge and above the plane of the grate such nozzle being adapted to project a steam jet towards the fire door and parallel to the plane of the grate.

In testimony whereof I have afiixed my signature.

HUGO SEROG. 

